Electronic cards or integrated circuit cards have considerably developed over the last few years. Initially, electronic cards were formed of a card body including a resistive contact module housed in a recess in the body of the card. Then, contactless cards were made, i.e. cards including a transponder formed of an electronic circuit connected to an antenna. As electronic cards have developed, it is sought to integrate other electronic elements for other functions into the cards. By way of example, cards including a switch that can be activated by the user and an electronic display have been disclosed. Such cards generally require relatively large batteries or powering means of the photovoltaic cell type. In order to integrate these various elements in a card, they are generally grouped together in the form of at least one electronic module, including a support, on the surface of which various electronic elements are arranged. FIG. 1 shows a schematic example of this type of module. Module 2 includes an integrated circuit 4, connected to an electronic display 6, a battery 8 and an activator 10, arranged on a support or substrate 12, forming a PCB interconnecting these various elements. In order to limit the thickness of these modules, the battery and/or the display can be arranged at the periphery of support 12 or in recesses therein.
It is not easy to integrate a relatively large electronic module, made up of various elements of variable shape and size, in a card. Further, integrating a digital display, which has to be precisely positioned in the manufactured card, causes an additional problem, which the present invention proposes to overcome.
EP Patent No. 0 570 784 discloses, in one implementation, a method of manufacturing cards including an electronic unit, in particular, a transponder, which is placed in a main aperture in a positioning frame. According to the implementation disclosed, the transponder and the positioning frame are embedded in a binding agent that can be added in liquid viscous form, particularly a resin. The positioning frame in EP Patent No. 0 570 784 is used only for delimiting an inner zone for the transponder, formed of an integrated circuit and a coil, inside the card. Thus, when pressure is applied to the various elements and the binding agent to form a card, the transponder is held in an inner zone, whereas it is possible for the binding agent, in a non-solid state, to flow to form a layer that passes through the manufactured card. Those skilled in the art can find, in this Patent document, a method for integrating a relatively large and complex-shaped electronic module in a compact, flat card. However, the electronic module placed in the main aperture in a positioning frame, as described in that document, will often be moved slightly when the card is being formed. Indeed, this document does not disclose how to maintain the transponder in a precise, determined position inside the aperture in the positioning frame. Those skilled in the art might certainly think of reducing the dimensions of the main aperture to make them approximately match the dimensions of the electronic module, in particular the external profile of the module. However, manufacturing tolerances must be taken into account, so that it is difficult to envisage too tight a fit. Moreover, depending upon the way in which the modules are manufactured, the positioning of the various elements on the support may also vary slightly. Thus, for example, digital display 6 is arranged on the surface of the PCB or at the periphery thereof in a position that may vary slightly. However, to obtain a high quality card, this digital display must be positioned precisely relative to the external contour of the manufactured card. This is particular important when a transparent aperture, which fits the dimensions of the digital display, is arranged above the aperture to allow the user of the card to read the display.
There is a further problem in addition to this problem of positioning the electronic module relative to the external contour of the card. This problem concerns introduction of the electronic module at the centre of the card manufacturing installation. It will be noted here that electronic cards are generally manufactured in batches, i.e. several cards are manufactured simultaneously in the form of a plate that includes a plurality of electronic modules. Then, each card is separated from the plate during a cutting step, as is described in EP Patent No. 0 570 784. Within the scope of the latter disclosure, the transponder remains free in relation to the positioning frame until the card is formed. This requires precautions in the handling of the various elements provided to form the card, to ensure that the transponders remain in the corresponding apertures of the positioning structure until the press is activated.
The present invention thus also proposes to answer this latter problem, identified within the scope of the present invention, so as to simplify the provision of electronic modules while ensuring that the electronic modules are kept in the apertures of a positioning structure and to facilitate assembly of the various elements and materials provided for manufacturing the cards.